Extension builders in Harrow

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.3 (16 reviews)

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Some of our top rated extension builders in Harrow

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BOTNARI CONSTRUCTION
Rating: 4.4 out of 5
Extension Builder in Harrow
We provide a service of maximum quality and client satisfaction . Having over 25 years experience in the field we have completed jobs big and small to the best standard .
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Latest review:
Electrical- 26 Jul 2026
Genuinely one of the worst builders we have come across. David rewired the flat and Stefan plastered the hallway. David is NOT qualified as an electrician and cut corners wherever he could. David leveraged us for money mid job and in the end left the job without finishing and without providing a certificate. David ran cables behind door frames (awful idea), got the cheapest material, forgot where holes were for spotlights and switches among many issues which meant we had to constantly ask our builders to fill the holes and make good. Stefan did the hallway plastering without putting on mesh. The plaster cracked within 2 weeks and the paint keeps cracking and will be a constant problem. When asked to come back and fix the issue - he point blank refused. They were the cheapest quote but we really hope we had gone to someone else
Bujar Vata
Rating: 5 out of 5
Extension Builder in Harrow
I am in the building business for 15 years I have worked all around London specially in the City I have registered myself on Mybuilders.com so I can get job around my area.
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Latest review:
Tiling- 7 Jun 2026
Amazing job and a brilliant team of tradespersons. An excellent job of the herringbone tile flooring with underfloor electric heating for the whole of my downstairs. The wall panels also complemented the flooring and were installed perfectly. Well done to Bujar and his team!
Parrot Decorators Limited
Rating: 4.7 out of 5
Extension Builder in Harrow
🦜 Parrot builders Ltd offers a comprehensive service specialising in loft conversion, extensions,conversion and refurbishment We hold over 10 years experience within the construction industry providing a high quality of work
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Latest review:
Conversions - General- 21 Nov 2017
Hard working! arrived when he said he would and completed just as he said he would. Will I hire again, YES, looking to get a quote on a loft extension next. thank you for your hard work. see you again soon.
Blueline Enterprise Limited
Rating: 5 out of 5
Extension Builder in Harrow
Blueline Enterprise is a family run firm specialising in high quality refurbishments, extensions, conversions and new builds. We have undertaken various projects through professional architects and private clients. We a reputable building construction firm based predominantly in North West London.
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Latest review:
Blueline completed the work to the exact high standard i was hoping for, while remaining on budget and estimated timescales - the three things that were most important to us! They were punctual, practical, knowledgeable and willing to give advice when either needed or when something could potentially be improved. They were always available to talk through what was happening at every stage of our job, with any complications arising, and importantly solutions to any problems. They knew their stuff and got the job done without any hassle either. They even came back after the job was finished to shift some pipework which i had an extra requirement for. The best feedback i could give is that we will go straight to them for any work we require in the future, and have already recommended them to friends.
Swiftfix
Rating: 5 out of 5
Extension Builder in Harrow
Trusted and reliable specialist in painting & decorating, tiling, and flooring. We combine high-end finishes with a friendly, professional approach, delivering clean, precise work with great attention to detail. Whether it’s a small job or a full renovation, we take pride in every project and always aim to exceed expectations. Quality work, honest service, and results you’ll be proud of.
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Latest review:
Really pleased with the full bathroom renovation and painting throughout the house. Great quality work, very professional and reliable. Everything looks amazing. Would definitely recommend!
Mr Mindaugas Bulevicius
Rating: 5 out of 5
Extension Builder in Harrow
MBL Carpentry ltd with over 18 years experience undertake all kind of building jobs from kitchens, bathrooms, extensions. No job is too big or too small.
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Latest review:
Carpentry- 1 Oct 2025
Great worker and reliable his price for the job was excellent and reasonable as other quotes were outrageous
Switch Electric Services Limited
Rating: 4.9 out of 5
Extension Builder in Harrow
A fully qualified electrician is a highly skilled professional equipped with comprehensive knowledge and expertise in all aspects of electrical work. With rigorous training and practical experience, they excel in designing, installing, and maintaining electrical systems with utmost precision and safety. From residential wiring to industrial installations, fully qualified electricians play a crucial role in powering the modern world, enabling progress, and illuminating our lives.
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Latest review:
Electrical- 9 May 2026
He was good on price for the first inspection and attended as agreed. However, I was less happy with the remedial quote. Several items quoted did not appear to be needed, while some items that did need attention were not included. Overall, fine for the inspection, but I would have preferred a more accurate and practical quote for the follow-up work.
Vertex Projects
Rating: 5 out of 5
Extension Builder in Harrow
Vertex Projects is a professional and trusted construction partner dedicated to bringing your vision to life. We specialise in a comprehensive range of services, including painting and decorating, building extensions, expert demolition, and plastering. Our expertise also extends to new fencing and the custom construction of bespoke balconies. At Vertex Projects, we pride ourselves on being a respectful team that treats every home and site with care, ensuring high-quality craftsmanship and a seamless experience from start to finish.
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Latest review:
Hard Flooring- 7 Jul 2026
Straight forward process with no hiden costs. The work was completed to a good quality with the new flooring in the garden outhouse and the waste removed. Will hire again in the future.
musul ltd
Rating: 3.5 out of 5
Extension Builder in Harrow
We do all types of maintenance works and specialise on extensions and loft conversions. We have in house planners and full time builders on site. We are based out of 3 offices in harrow/ Ealing /Knightsbridge.
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Latest review:
Tiling- 6 Oct 2022
We are beyond shocked and disgusted by his awful behaviour. Initially, he acted professional and trustworthy, but he turned out to be exactly the opposite. On the 8th of July, he promised "3-5 working days" instead he pulled us along for two months of unbearable stress and waste of time because he kept on taking other jobs instead of doing ours. He wasted all of July as we had to meet him four times to finalize the design that he kept on rejecting until we agreed on the easiest option for him. He dragged out removing tiles and levelling 10 steps all of August, working 6 hours in total and leaving a job that is so appalling that it needs to be completely redone. He postponed the tiles' order for a month despite assuring us all August that he had done it in July; after numerous complaints, he sent the tiles' invoice, dated 31st of August. He gave us dozens of appointments but never came nor had the decency to cancel, despite dozens of calls, emails and texts, causing significant disruptions and loss to our life and work commitments. We asked him to reimburse the cost of the tiles and materials he didn't provide and for the work he didn't do, but he ignored our emails. We have removed him from the job and are reporting him to the relevant authorities.
TRT Construction
Rating: 5 out of 5
Extension Builder in Harrow
🔨 TRT Construction Ltd 🔨 Looking for reliable building, renovation, or home maintenance services? We provide professional, high-quality workmanship for residential and commercial projects. ✔ Building & Renovation ✔ Home Improvements ✔ Property Maintenance ✔ Reliable & Professional Service 📩 Contact us today for a free quote.
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Latest review:
Carpentry- 16 Sep 2026
Taha showed up quickly and did a decent job of installing architraves / Skirting. His attention to detail was on the level I was expecting and was nice to see.
Bricklayer
Rating: 5 out of 5
Extension Builder in Harrow
Brickwork . New build, extension . Garage
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Latest review:
Bricklaying- 10 Jul 2023
I am very pleased with the work done Excellent clean job Mr Bicol has carried out
Flynn Construction ltd
Rating: 5 out of 5
Extension Builder in Harrow
We are a medium sized Limited Company based in Watford . We specialise in all area's of building - New builds, Refurbishments, Extensions and Paving all welcome. We have a vastly experienced team to cater for all your building needs.
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Latest review:
Extensions- 12 Jun 2020
Gavin project managed the rear story extension on our house from start to finish and was professional and friendly throughout. He was always on hand to offer help and support and we would definitely recommend his services.
Adam Renovations Ltd
Rating: 5 out of 5
Extension Builder in Harrow
Adam Group Ltd is an established residential construction and development company, incorporated in 2010, specialising in high-quality refurbishments, extensions, loft conversions and new build projects across London and the South East. We work with homeowners, investors and local authorities on projects ranging from £150,000 to £3 million, covering everything from full house refurbishments and structural reconfigurations to large-scale extensions, loft conversions and ground-up developments. Since inception, we have successfully delivered over 250 projects, building a strong track record for reliability, quality and consistent delivery. In 2025 alone, the company achieved a turnover of £4.5 million, reflecting both our capacity and the level of projects we undertake. Our team provides an end-to-end service, including planning coordination, structural works and full construction delivery. We are experienced in working alongside architects, engineers and local authorities to ensure projects run smoothly and comply with all regulatory requirements. We maintain a 4.9-star rating on Google, with the majority of our work coming from repeat clients and referrals — a testament to our professional approach, clear communication and attention to detail. If you are planning a refurbishment, extension or new build and want a contractor with a proven track record and the capability to deliver complex residential projects, we would be happy to discuss your requirements.
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Latest review:
Loft Conversion- 5 May 2017
Artjom and his team have done a wonerful job on our loft conversion and house renovation. We are very pleased at the transformation. Although not the cheapest quote we obtained, they were highly professional, kept the noise down and cleaned up after themselves. We also added several other jobs to our initial quote and they undertook these as requested. It is important to keep a record of everything you ask to be done. They worked very fast and were able to complete everything within 2 months - it helped that our house was empty at the time, so they didn't have to deal with us living there at the same time as the works were being carried out. Overall, I would highly recommend Adam Renovations for any building works you need done to your property.
Ela Merite Solutions LTD
Rating: 5 out of 5
Extension Builder in Harrow
I am Tony i have over 15 years experience in construction industry.I am fully qualified for many types of construction work.
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Latest review:
Extensions- 30 Sep 2020
Bajram and his team did a great job building a utility room extension to our new house and rescued us from a very bad experience with a prior building company. The job was done at a competitive price and in good speed, not because it was rushed but because it was managed very well with enough man power at the right times. I was so happy that I subsequently got them to take on several other aspects of our full house refurbishment.
Sebastiano Vuksani
Rating: 5 out of 5
Extension Builder in Harrow
Build your dream with SV building construction ltd Regards
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Latest review:
Extensions- 30 Jan 2023
I had the pleasure of having them carry out a single story extension and fibreglass new roof of my property. I found they always turned up when specified and carried out fantastic quality work for a competitive price. Not being a builder you have to place trust in a person / company. They always made sure that we were happy keeping us updated with the project every step of the way. They were kind and considerate to our neighbours making sure they were not loud early in the morning or late in the evenings making the whole process run smoothly. I can not stress enough how great these guys are. Thanks
fta haliti ltd
Rating: 5 out of 5
Extension Builder in Harrow
FTA construction is a family run company that specialises in, Design and build projects inc, extensions, loft conversions, interior and exterior inc plumbing and electrician
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Latest review:
Driveways (Paved & Loose)- 1 Jun 2019
That’s was lovely job from ur company,well done guys ,highly recommended your company,very professional and tidy.Very happy with your company

4.3

Top rated Extension Builders

Our Extension Builders in Harrow, are rated 4.3 out of 5 based on 16 reviews from customers like you.

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What types of services are offered by local extension builders in Harrow?

Building an extension is a major milestone for any home. It’s not just about adding extra space, it’s a big step that can transform how you live day to day, opening up new possibilities for comfort, lifestyle, and family needs.

This is why it’s so important to find the right extension builders in Harrow for you. They can help with a variety of tasks and projects, including:

Extending your home with an extra room
Two+ storey extensions
Adding partition walls to create more rooms
Building annexes or external structures

To find the right extension builder near you, simply post your job on MyBuilder. Explain the type of help you’re looking for, and then home extension builders in Harrow who are available and interested can respond to your post.

Browse profiles, read customer reviews and get quotes from your chosen Harrow extension builders, all before you decide who to hire.

What are the hourly rates of extension builders in Harrow?

Before getting started with your extension project, it’s important to have a clear budget in place. On average, extension builders in Harrow will charge between £16 and £42 per hour.

Single-storey rear extensions cost between £20,000 and £60,000 depending on size and finish.
The cost of double-storey extensions, which add more space and value, can range from £100,000 to over £170,000.
Larger wrap-around extensions that combine multiple extension types can range from £40,000 to over £120,000.

The cost of an extension will vary depending on your property. For instance, extending in certain areas may require structural adjustments to ensure stability, which can increase your material and labour costs.

To get an accurate price for your home extension, request detailed quotes from several Harrow extension builders near you on MyBuilder. This allows you to compare what each quote covers and how much your Harrow home extension project is likely to cost.

Find extension builders in Harrow with MyBuilder

Hiring the right extension builder in Harrow with MyBuilder couldn’t be easier. Just follow these simple steps:

Step 1: Post your extension project on MyBuilder

Whether you’re planning a single-storey extension, a loft conversion, or adding a new room, post your job on MyBuilder to find local Harrow extension builders. Once your job is live, we’ll share it with home extension builders in Harrow who can express their interest.

Step 2: Compare different extension builders in Harrow

When you start receiving interest, review profiles of local Harrow extension builders, check their previous work, and read real customer reviews. Ask about timelines, materials, and request detailed quotes.

Step 3: Hire Harrow extension builders with confidence

After gathering all the information and quotes from your chosen home extension builders in Harrow, compare their experience, guarantees, and costs before choosing who to hire.

You’ll also have confidence knowing that every tradesperson on MyBuilder is verified through several checks, including:

ID verification: When a tradesperson joins MyBuilder, we ask for a valid ID, such as a passport, ID card, or eIDAS certificate.
Company verification: For tradespeople operating under a company, we make sure every tradesperson has a registered business.

Did you know? Our continuous monitoring and complaints process ensures that tradespeople who don’t meet our standards are promptly removed from MyBuilder’s platform.

Harrow extension builders are ready to help. Use MyBuilder today to find the right professional for your home extension.

What to ask a Harrow extension builder before hiring?

Before hiring an extension builder in Harrow or extension building company in Harrow, ask a few key questions to make sure you’re choosing the right professional for your home extension project.

What qualifications and experience do you have as an extension builder in Harrow?

An extension builder in Harrow should have a strong track record with similar projects and relevant building qualifications or trade memberships, such as the Federation of Master Builders (FMB) or TrustMark.

Will my home extension meet all building regulations and planning requirements?

Your Harrow extension builder should ensure the project complies with Building Regulations and, where necessary, handle or assist with planning permissions. Ask how they manage building control inspections and what documentation you’ll receive once the project is complete.

What experience do you have with similar extensions in Harrow?

Ask to see examples of their previous work, or view examples of their work on MyBuilder. Ideally projects similar to yours in scale and design. This helps you assess the Harrow extension builder’s ability to deliver a result that meets your expectations.

How long will the extension take to complete?

Extension project timelines can vary depending on size, complexity, and weather. A typical single-storey extension might take around 8 - 12 weeks. Request a detailed schedule so you know what to expect and when key milestones will be reached.

Do you offer a guarantee for your work? Most Harrow extension builders offer a guarantee or warranty on their work, often between 1 and 10 years depending on the project and materials used. This gives you assurance that any issues will be resolved after completion.

If you still have questions about the professional you are looking to hire, we have a full detailed guide on hiring the right builder here.

FAQ: Common questions about home extensions in Harrow

Can an extension builder in Harrow help with planning permission?

Yes, many extension builders in Harrow can guide you through the planning process. They can help prepare drawings, advise on local requirements, and liaise with your local council to ensure your project meets all necessary regulations.

Can an extension builder in Harrow handle everything from design to construction?

Many Harrow extension builders offer full design-and-build services, managing both the architectural planning and construction stages. Ask your builder whether they can provide a complete package or if you’ll need to hire an architect or designer separately.

Will an extension builder in Harrow help with materials and finishes?

Yes, most extension builders in Harrow can source materials and offer advice on finishes that suit your design and budget. You can also choose to supply certain materials yourself, just make sure this is agreed upon before work starts.